Pool Alkalinity Calculator
Total alkalinity (TA) keeps your pH stable. Target range: 80鈥?20 ppm. The standard fixer is ordinary baking soda (sodium bicarbonate) 鈥?the same box from the grocery store.
How the math works
- Baking soda: 1.5 lbs per 10,000 gallons raises TA by about 10 ppm 鈫?lbs = 螖ppm 脳 gallons 梅 10,000 脳 0.15
- Soda ash: 1 lb per 10,000 gallons raises TA by about 11 ppm, but it also pushes pH up 鈥?use it when both TA and pH are low
Before you add
- Test TA with a reliable test kit (drop-based tests are more accurate than strips).
- Add baking soda in two or three portions, brushing between doses, rather than all at once.
- Retest after 4鈥? hours of circulation. If pH drifts up too much after soda ash, use muriatic acid to bring it back down.
- Never mix chemicals together 鈥?always add one product at a time, with the pump running.
Frequently asked questions
Can I use Arm & Hammer baking soda from the grocery store?
Yes. Grocery-store baking soda and "alkalinity increaser" pool chemicals are the same compound (sodium bicarbonate). The pool-store version is often just repackaged 鈥?and more expensive.
My TA is high. How do I lower it?
Lower TA with muriatic acid, then aerate (returns, spa jets, air compressor) to raise pH back up without raising TA. Repeat as needed 鈥?this is called the acid/aeration method.
Why does my pH keep drifting up?
Rising pH with falling TA usually means aeration (waterfalls, spillovers, features) is driving CO鈧?out of the water. Lower TA into the 60鈥?0 ppm range to make pH easier to hold.